Pemphigus vulgaris (PV) is an autoimmune condition. An autoimmune condition causes the body's immune system to attack its own cells and organs by mistake.
Normally, the immune system only responds like this to an invading germ or substance that it does not recognise, such as a virus or pollen.
In the case of PV, the immune system produces antibodies that damage the cells in the skin and mucous membranes (the lining of the mouth, nose, throat and genitals). The antibodies attack proteins called desmogleins, which hold the cells together. This causes the cells to fall apart. Fluid-filled blisters or sores then develop in the spaces.
It is not known why some people develop this reaction.
Is PV inherited?
PV is not passed down through families, and it is very unusual for more than one person in a family to have PV.
However, recent evidence suggests that the genes a person inherits from their parents, while not directly causing PV, may make them more susceptible to the disease.
Two genetic mutations (where the instructions found in all living cells become scrambled in some way) called DR4 and DRw4 are common in people with PV.
Most experts believe it also takes an external factor or combination of factors to trigger PV. This could be a bacterial or viral infection or something in the environment, such as a pollutant.
